Recent years have seen an increased demand for inexpensive apparel and the development of new and inexpensive components of construction and methods of construction of articles of apparel. In certain instances, there is a demand for apparel that is very inexpensive and, indeed, disposable. New elastomeric materials and methods of incorporating them into portions of a garment have been developed to meet the desire to fit these types of garments to a human form. For example, U.S. Pat. No. 3,639,917 discloses the use of a strip of a heat recoverable elastomeric material to gather the cuff of a disposable hospital gown.
Disposable diapers have been marketed which include an elastic or stretch member in the longitudinal side edges of the disposable diaper to provide elasticity about the leg of the infant when the diaper is applied. Examples of such stretchable fitted diapers which have elastic members disposed in the longitudinal side edges of the diaper are shown in U.S. Pat. Nos. 3,860,003 and 4,050,462. By being able to elastically contract the longitudinal sides of the diaper which are the leg and thigh encircling portion of the diaper once placed on an infant, you can compress the diaper about the leg of the infant. By virtue of this compressing, you reduce leakage at the leg of the infant and the tighter you make the fit, the more you tend to reduce leakage. However, if the fit is too tight, you will cause irritation on this tender portion of the thigh, especially when the diaper is wet. There are also a number of patents which disclose means for making the waist encircling portion of a disposable diaper elastic for tighter fit of the diaper about the waist of the wearer, for example, as shown and described in U.S. Pat. Nos. 3,995,637 and 3,995,640. Disposable diapers usually comprise a facing and a backing layer which are substantially co-extensive and a somewhat smaller absorbent core or panel interposed between the facing and backing layer. The facing and backing layers are adhered together about their perimeter by hot melt adhesive or other adhesive material as is well known. In producing stretch or elastic diapers, an elastic member in its stretched or partially stretched state, is interposed between the facing and backing sheets along one or more edges of the diaper. The elastic member is adhered either to the facing and/or the backing sheets by adhesive or similar means and allowed to relax to produce elastic sections at the edges of the diaper. An example of a method for inserting elastic members in disposable diapers is disclosed in U.S. Pat. No. 4,081,301.
The incorporation of these elastic members into disposable diapers has increased both the cost of materials used in the diaper and the cost of construction of disposable diapers. With solid elastic members, it is necessary to adhere the side edges of the facing and backing sheets together, either directly or by their mutual attachment to the elastic member.
When adhesively securing such an elastic member into a disposable diaper, the adhesive chosen must be elastomeric or must be applied in a discontinuous pattern or the glue may make the diaper too stiff to gather.
In commonly assigned co-pending patent application, Ser. No. 60,704 filed July 25, 1979, there is disclosed apertured elastic members which have substantial advantages over other types of elastic members in that they are simpler and more economical to insert and function very well by providing a good fit with a minimum of irritation. The present invention is an improvement on such apertured elastic members.
The laminated structures of the present invention provide improved fit about the portion of the human body to which they are applied. In the various parts of the extremities of the human body, such as the wrist, thigh, etc., the circumference of the extremity increases as you move along that extremity towards the body torso. Therefore, an elastic of any width will apply different forces on that extremity with the most force and the primary seal usually being at the contact line between the elastic and the body part having the greatest circumference.
Contrasted to the above, the apertured elastic member used in the laminated structures of the present invention has a varying degree of tension across its width and can be used to apply uniform forces about and along the extremity or even to apply the greatest force at the contact line between the elastic and the body part having the least circumference. The laminated structures of the present invention provide not only an improved fit but unexpectedly improve sealing capabilities with a minimum of irritation.